Find the annual dividend received by Nishita from $1200$ preferred shares and $3000$ common shares,both of par value $Rs. 50$ each,if the dividend paid on preferred shares is $10 \%$ and a semi-annual dividend of $3 \frac{1}{2} \%$ is declared on common shares. (in $Rs.$)

$A$ man bought $Rs. 20000$ of $5\%$ stock at $90$ and sold it when its price rose to $Rs. 93 \frac{3}{4}$. Find out his gain percent.

$Rs. 555$ was to be divided among $A, B$ and $C$ in the ratio of $\frac{1}{4}: \frac{1}{5}: \frac{1}{6}$. But by mistake,it was divided in the ratio of $4: 5: 6$. The amount in excess received by $C$ was (in $Rs.$)

What investment will be required to purchase $Rs.\, 90000$ of $8 \%$ stock at $110$?

Sonu invested $10 \%$ more than Mona. Mona invested $10 \%$ less than Raghu. If the total sum of their investment is $Rs. 5780$,how much amount did Raghu invest? (in $Rs.$)

The capital of a company is made up of $50000$ preferred shares with a dividend of $20 \%$ and $20000$ common shares,the par value of each type of share being $Rs. 10$. The company had a total profit of $Rs. 180000$,out of which $Rs. 30000$ were kept in a reserve fund and the remaining was distributed to shareholders. Find the dividend percentage for the common shareholders (in $\%$).